Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss), Net Of Tax, In The Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Other Comprehensive Income (Loss) [Abstract]
Beginning balance of URA (D) on securities			$ 13,654	$ 37,628	$ 37,628
Current period change in URA (D) of investments - temporary			83,027		(30,257)
Current period change in URA (D) of investments - non-credit OTTI			2,730		6,283
Ending balance of URA (D) on securities	$ 99,411		99,411		13,654
Beginning balance of foreign currency translation adjustments			(12,701)	41,877	41,877
Current period change in foreign currency translation adjustments			27,779		(54,578)
Ending balance of foreign currency translation adjustments	15,078		15,078		(12,701)
Beginning balance of benefit plan net gain (loss)			(63,089)	(74,986)	(74,986)
Current period change in benefit plan net gain (loss)	1,268	$ 1,556	3,949	$ 4,769	11,897
Ending balance of benefit plan net gain (loss)	(59,140)		(59,140)		(63,089)
Ending balance of accumulated other comprehensive income (loss)	$ 55,349		$ 55,349		$ (62,136)